Isolation Improves Samsung Image Sensor

Samsung Electronics Co. Ltd. has announced that it has developed a CMOS image sensor pixel technology that reduces cross-talk between near neighbors, increases light sensitivity, and provides better color fidelity in low light conditions.

The improvement is achieved by including an additional barrier between adjacent pixels and Samsung calls the technology Isocell, Samsung said in a press release. The S5K4H5YB 8-megapixel device is the first image sensor to use the technology. The sensor has 1.12 micron pixels and comes in a 0.25-inch optical format. The S5K4H5YB is currently sampling to customers with mass production scheduled for 4Q13.

The S5K4H5YB 8-megapixel CMOS image sensor from Samsung is the first image sensor to use the Isocell technology to improve full-well capacity. Source: Samsung.

CMOS image sensors have been challenged by the twin requirements of increasing pixel counts -- for improved resolution -- while limiting or even reducing die size to reduce cost. Back side illumination (BSI) was the latest innovation used to try and maximize pixel area and light absorption.

The Isocell isolation technology, which is patent pending, uses BSI but allows more photons to be collected from the lens and absorbed at the correct pixel and increases the so-called full well capacity (FWC) of each pixel. Isocell pixels increase the FWC by 30 percent compared to conventional BSI pixels, which increases the dynamic range, and decreases crosstalk by approximately 30 percent, Samsung said.

In addition Isocell arrays can take in light from a 20 percent wider angle thereby reducing the height of the camera module, a feature desired by phone designers.